Can one GPX file contain several tracks?

Yes, and it is a common source of trouble: many devices read only the first one, or reject the whole file. One GPX per track remains the safest shape for transferring.

Can a GPX be edited by hand?

Yes, it is text: fixing a name or deleting a waypoint in an editor works fine. Removing points by hand, on the other hand, goes wrong quickly — better a tool that recomputes the distances behind you.

Why does my file show no ascent?

Because it holds no elevation. That is the case for most routes drawn on a map rather than recorded in the field. An honest reader then shows a map with no profile instead of estimating a figure.

Does a GPX contain personal data?

It contains where you were and when, which is often enough to say where you live: a track recorded from home starts at your front door. That is why the tools on this site read files inside the browser and never send them anywhere.

What is a GPX file?

A GPX file is a journey written down: a series of coordinates, in the order you walked them or the order you intend to. It contains no map of its own — the map comes from whatever opens it.

A text file you can read as it is

GPX stands for GPS Exchange Format. It is XML, which is to say tagged text: open a GPX in a text editor and you can read it line by line, each point carrying its latitude and longitude. Nothing is encrypted, nothing is compressed. That is why it has lasted — the format has not changed since 2004, and a device from fifteen years ago still reads a file exported this morning.

Track, route, waypoint: three different things

A GPX can carry three kinds of content, and confusing the first two causes most of the unpleasant surprises. A track is a recording: thousands of points logged second by second, the path actually taken. A route is an intention: a handful of points the device joins up itself, its own way. Waypoints are named places, independent of the path. The same outing described as a track or as a route yields neither the same file nor the same length.

What a GPX does not contain

No map, no photo, no colour, no trail name. A GPX describes positions and nothing else; everything you see around the line on screen — the relief, the contour lines, the villages — comes from the basemap of the software showing it, not from the file. That is why the same track looks different from one reader to the next, without either of them being wrong.

Elevation and time are optional

Plenty of files carry an elevation and a timestamp for every point, but nothing requires it. A route drawn by hand on a planning site usually has neither: there is then no ascent to compute, no speed, no duration. When elevation is present, its accuracy depends on where it came from — a barometer follows the terrain closely but drifts with the weather, while GPS alone is easily several metres out vertically.

Where GPX files come from

From a watch or a bike computer, exporting the ride once you are home; from a route planning site offering the download; from a guidebook or a tourist office attaching the file to its page; from a companion who emails it over. It is the same format every time, and it depends on no account and no service.

GPX, TCX, KML, FIT: which is for what

GPX is the exchange format: the one almost everything reads and writes. TCX comes from training devices and adds effort data — heart rate, cadence — to the same line. KML is built for cartographic display, with its styles and layers, but describes a shape rather than a journey through time. FIT is binary, compact, and specific to the devices that write it. When in doubt about what to ask someone for, ask for GPX.

What you find inside

The track points: A long list of coordinates, each with its latitude and longitude, in order. This is the heart of the file, and often tens of thousands of lines for a single day on foot.
Elevation, when present: One value per point, in metres. Ascent and the elevation profile are derived from it; without it a reader can only draw a flat map — and it is right not to invent the rest.
Time, when present: A timestamp on each point, the only possible source for a duration, a speed or a pause. A route planned in advance has none: nobody has walked it yet.
The waypoints: Named points, independent of the line: a hut, a spring, a pass, a trailhead. They carry a name and sometimes a description, and a good many readers ignore them entirely.
The segments: A track can be cut into several pieces. A break marks a pause, a lost signal or a change of day — and a serious reader does not join the two ends, because the straight line it would draw adds a distance nobody covered.
The name and the device: A title for the track, and often a mention of the hardware or software that produced it. That is what appears at the top when a reader opens it — and why so many files are still called "Track 001".

See what yours contains

The quickest way to know what a file holds is still to open it. The viewer on this site reads it in your browser and shows what it finds: the line, the distance, the ascent when there are elevations, the waypoints when there are any. The file never leaves your device, and nothing is kept.

Open my GPX file

Frequently asked questions

Can one GPX file contain several tracks?: Yes, and it is a common source of trouble: many devices read only the first one, or reject the whole file. One GPX per track remains the safest shape for transferring.
Can a GPX be edited by hand?: Yes, it is text: fixing a name or deleting a waypoint in an editor works fine. Removing points by hand, on the other hand, goes wrong quickly — better a tool that recomputes the distances behind you.
Why does my file show no ascent?: Because it holds no elevation. That is the case for most routes drawn on a map rather than recorded in the field. An honest reader then shows a map with no profile instead of estimating a figure.
Does a GPX contain personal data?: It contains where you were and when, which is often enough to say where you live: a track recorded from home starts at your front door. That is why the tools on this site read files inside the browser and never send them anywhere.